#!/usr/bin/env python
"""
Matrix-Based Encodings for HDC
HDC-compatible wrapper for VTB and MBAT encodings.
"""
import numpy as np
from pyhdc.components.binding import (
InverseMatrixMultiplication,
MatrixMultiplication,
TransposeVectorDerivedTransformation,
VectorDerivedTransformation,
)
from pyhdc.components.bundling import ElementAdditionNormalized
from pyhdc.components.elements import NormalReal
from pyhdc.components.similarity import CosineSimilarity
from pyhdc.components.thinning import NoThin
from pyhdc.encodings.base import Encoding
from pyhdc.hypervector import EncodingSpec
# ============================================================================
# Matrix-Based Encodings
# ============================================================================
[docs]
class VTB(Encoding):
"""
Vector-derived Transformation Binding.
Uses vector-derived transformations for binding operations.
"""
def _get_encoding_spec(self) -> EncodingSpec:
return EncodingSpec(
dtype=np.float32,
element_generator=NormalReal,
similarity_fn=CosineSimilarity,
bundling_fn=ElementAdditionNormalized,
thinning_fn=NoThin,
binding_fn=VectorDerivedTransformation,
unbinding_fn=TransposeVectorDerivedTransformation,
generator_output_type="floats",
)
[docs]
class MBAT(Encoding):
"""
Matrix Binding of Additive Terms.
Uses matrix multiplication for binding operations.
"""
def _get_encoding_spec(self) -> EncodingSpec:
return EncodingSpec(
dtype=np.float32,
element_generator=NormalReal,
similarity_fn=CosineSimilarity,
bundling_fn=ElementAdditionNormalized,
thinning_fn=NoThin,
binding_fn=MatrixMultiplication,
unbinding_fn=InverseMatrixMultiplication,
generator_output_type="floats",
)